1. Field of the Invention
The present invention relates to a ceramic material having a perovskite structure. The present invention also relates to an electronic device and more particularly to a capacitor intended for high temperature applications.
2. Description of the Related Art
Conventionally, an SiC integrated circuit that can operate in a high temperature about from 25° C. to 400° C. is used in a hard condition such as a vehicle. The SiC integrated circuit includes a capacitor, and the capacitor includes a dielectric layer made of a high-permittivity material.
The high-permittivity material is broadly classified into a high-permittivity gate insulating material represented by a SiO2-based material and a HfO2-based material (hereinafter called the material 1) and a perovskite-type oxide represented by BaTiO3 (hereinafter called the material 2). Regarding the material 2, a temperature stability of permittivity can be improved by replacing a part of Ba with Sr as described in A. D. Hilton and B. W. Ricketts, J. Phys. D: Appl. Phys., 29 (1996) 1321-1325.
The material 1 has a difficulty that the permittivity is as small as 10 to 20. The material 2 has a difficulty that the permittivity greatly changes with temperature, that is, the temperature stability of permittivity is low.